Ok, I may end up sounding like an idiot by putting my two cents worth in on this thread but if it can happen to me it can happen to anyone and often the most parsimoneous explaination is the right one.
I had a stalling event several times while in slow traffic waiting at an intersection. I had the car in neutral at Idle with my foot on the clutch and it would just die. Always started up right away afterward but this probably happened five or six times before I figured out what it was. Turns out that at Idle, if the clutch is even the slightest bit not all the way down there is enough drag to stall the car. The problem was that I was allowing my foot to come up just a tiny fraction of measure and I was the problem with the car, not the car itself. So...when I read this thread, my first question is while in neutral coast did you or did you not have your foot on the clutch and have it FULLY depressed. Hell, I've driven lots of cars with a stick and never had this problem before but the GT is so sensitive to this that it happened. Just asking the question. Not intending to insult anyone...